| Scientific Name | Common Name(s) | Life History | Growth Form | |
|---|---|---|---|---|
|
Polygala myrtifolia | Myrtle-leaf milkwort, butterfly-bush, parrotbush | Perennial | shrub |
| Polygonatum glaberrimum | Solomons seal | Perennial | forb | |
|
Poncirus trifoliata | hardy orange | Perennial | tree |
|
Populus alba | White Poplar | Perennial | tree |
| Portulaca grandiflora | rose-moss, Mexican-rose, eleven-o'clock, moss-rose, sunplant | Annual | forb | |
|
Potentilla recta | sulphur cinquefoil, rough-fruit cinquefoil, erect cinquefoil | Perennial | forb |
| Prunus mahaleb L. | Mahaleb cherry, Saint Lucie's cherry | Perennial | tree | |
|
Puccinellia maritima | seaside alkaligrass | Perennial | grass |
| Pulicaria paludosa | Spanish false fleabane, Spanish sunflower | Annual | forb | |
| Punica granatum 'Favorite' | pomegranate, Granada (Spanish) , granado (Spanish), mangrano (Spanish) | Perennial | tree | |
|
Pyracantha coccinea | scarlet firethorn | Perennial | shrub |
|
Pyrus calleryana | Callery pear, Bradford pear | Perennial | tree |
|
Pyrus calleryana 'Bradford' | Bradford pear | Perennial | tree |
| Pyrus calleryana 'Glen's Form' CHANTICLEER | callery pear, chanticleer pear, cleveland select pear, stonehill pear, faurie pear, flowering pear | Perennial | tree | |
|
Pyrus ussuriensis | Ussurian Pear, Chinese Pear, Manchurian Pear | Perennial | tree |
|
Quercus acutissima | Sawtooth Oak | Perennial | tree |
| Quercus polymorpha | Monterrey Oak, Mexican White Oak, Texas White Oak | Perennial | tree | |
| Quercus rysophylla | Loquat oak | Perennial | tree | |
| Quercus xalapensis | PETZALÁHUATL, Xalapa oak | Perennial | tree | |
|
Ranunculus arvensis | field buttercup, corn buttercup, corn crowfoot, hungerweed, scratch bur, devil-on-all-sides, hellweed, Devil's claws | Annual | forb |
|
Rapistrum rugosum | turnipweed, ball-turnip, bastard-cabbage, giant mustard, wild turnip | Annual | forb |
|
Reynoutria japonica | Japanese knotweed, Asian knotweed | ||
| Reynoutria japonica 'Devon Cream' | Japanese knotweed, Japanese fleeceflower | Perennial | forb | |
| Reynoutria japonica 'Variegata' | variegated Japanese knotweed, variegated Japanese fleeceflower, speckled Mexican bamboo | Perennial | forb | |
| Rhagadiolus stellatus | Star endive, Endive daisy, Star hawkbit | Annual | forb |